Refrigerating device

Abstract

A refrigerating device includes a refrigerant circuit, a temperature detecting unit, a protection control section, and a determination temperature modifying section. The refrigerant circuit includes a compressor to compress a refrigerant. The temperature detecting section detects a temperature of the refrigerant discharged from the compressor on an outside of the compressor. The protection control section performs protection control of the compressor in a case where a detection temperature detected by the temperature detecting section exceeds a determination temperature. The determination temperature modifying section modifies the determination temperature according to at least one of information on an outside air temperature and information on a type of the refrigerant.

What is claimed is: 
     
       1. A refrigerating device comprising:
 a refrigerant circuit including a compressor arranged and configured to compress a refrigerant and an expansion valve in which an opening degree is adjustable; 
 a temperature detecting section arranged and configured to detect a temperature of the refrigerant discharged from the compressor on an outside of the compressor; 
 a protection control section configured to compare the detection temperature detected by the temperature detecting section to a first determination temperature, a second determination temperature larger than the first determination temperature, and a third determination temperature larger than the second determination temperature, and to perform a protection control of the compressor by:
 reducing the driving frequency of the compressor in a case where the detection temperature exceeds the first determination temperature but does not exceed the second determination temperature, 
 increasing the opening degree of the expansion valve in a case where the detection temperature exceeds the second determination temperature but does not exceed the third determination temperature, and 
 stopping the compressor in a case where the detection temperature exceeds the third determination temperature; and 
 
 a determination temperature modifying section configured to modify the determination first, second and third temperatures according to at least one of information on an outside air temperature and information on a type of the refrigerant, the first, second, and third determination temperatures being modified so that a temperature inside the compressor is maintained under a predetermined overheating temperature of the compressor, 
 the compressor being an inverter control compressor capable of varying driving frequency, and 
 the determination temperature modifying ng section further modifying the determination temperature according to the driving frequency. 
 
     
     
       2. The refrigerating device according to  claim 1 , wherein
 the determination temperature modifying section modifying the determination temperature to be a smaller value as the outside air temperature falls. 
 
     
     
       3. The refrigerating device according to  claim 1 , wherein
 the determination temperature modifying section modifying the determination temperature to be a smaller value as a ratio of specific heat of the refrigerant is larger. 
 
     
     
       4. The refrigerating device according to  claim 1 , wherein
 the determination temperature modifying section modifying the determination temperature to be a smaller value as the driving frequency is smaller. 
 
     
     
       5. The refrigerating device according to  claim 1 , wherein
 the temperature detecting section arranged and configured to detect an instantaneous temperature of the refrigerant discharged from the compressor on an outside of the compressor.